Process for the production of olefins

Abstract

The present invention relates to a process for the production of an olefin, said process comprising passing a mixture of a hydrocarbon and an oxygen-containing gas through a catalyst zone which is capable of supporting combustion beyond the fuel rich limit of flammability to produce said olefin, said catalyst zone comprising at least a first catalyst bed and a second catalyst bed, and wherein the second catalyst bed is located downstream of the first catalyst bed, is of a different composition to the first catalyst bed and has the general formula of: M 1 a M 2 b M 3 c O z wherein M 1 is selected from groups IIA, JIB, IIIB, IVB, VB, VIIB, VIIB, lanthanides and actinides, M 2 is selected from groups IIA, IB, JIB, IIIB, IVB, VB, VIB, and M 3 is selected from groups IIA, IB, IIB, IIIB, IVB, VB, VIB and VIIIB.

1 - 9 . (canceled)  
   
   
       10 . A process for the production of an olefin, said process comprising passing a mixture of a hydrocarbon and an oxygen-containing gas through a catalyst zone comprising at least a first catalyst bed and a second catalyst bed, wherein the first catalyst bed comprises a catalyst which is capable of supporting combustion beyond the fuel rich limit of flammability and wherein the second catalyst bed is located downstream of the first catalyst bed, is of a different composition to the first catalyst bed, has the general formula of:  
       M 1   a M 2   b M 3   c O z    
     wherein M 1  is selected from groups IIA, IIB, IIIB, IVB, VB, VIIB, VIIB, lanthanides and actinides, M 2  is selected from groups IIA, IB, IIB, IIIB, IVB, VB, VIB, M 3  is selected from groups IIA, IB, IIB, IIIB, IVB, VB, VIB and VIIIB, a, b, c and z are the atomic ratios of components M 1 , M 2 , M 3  and 0 respectively, a is in the range of 0.1 to 1.0, b is in the range of 0.1 to 2.0, c is in the range of 0.1-3.0, and z is in the range 0.1 to 9, and has a perovskite-type structure.  
   
   
       11 . A process according to  claim 10  wherein the first catalyst bed comprises a Group VIIIB metal.  
   
   
       12 . A process according to  claim 11  wherein the first catalyst bed is selected from the group consisting of Pt/Ga, Pt/In, Pt/Sn, Pt/Ge, Pt/Cu, Pd/Sn, Pd/Ge, Pd/Cu and Rh/Sn.  
   
   
       13 . A process according to  claim 10  wherein M 1  is selected from group IIIB, M 2  is selected from group IIA and M 3  is selected from group IB.  
   
   
       14 . A process according to  claim 13  wherein M 1  is yttrium, M 2  is barium and M 3  is copper.  
   
   
       15 . A process according to  claim 10  wherein the second catalyst bed is promoted by addition of halide-promoters to yield materials having the general formula of;  
       M 1   a M 2   b M 3   c X x O z    
     wherein X is a halide and x is in the range of 0.05-0.5.  
   
   
       16 . A process according to  claim 10  wherein the hydrocarbon is a paraffin-containing feed comprising hydrocarbons having at least two carbon atoms.  
   
   
       17 . A process according to  claim 10  wherein the molar ratio of hydrocarbon to the oxygen-containing gas is 5 to 16 times the stoichiometric ratio of hydrocarbon to oxygen-containing gas required for complete combustion of the hydrocarbon to carbon dioxide and water.  
   
   
       18 . A process according to  claim 10  wherein hydrogen is co-fed with the hydrocarbon and oxygen-containing gas into the reaction zone.